1. Field of the Invention
The present invention generally relates to an image-formation device and a process cartridge used in such a device. The present invention particularly relates to a process cartridge which includes both a photosensitive-body case containing a photosensitive drum and a development-body case containing a development roller, and relates to a method of manufacturing such a process cartridge. Further, the present invention relates to a shutter mechanism of the process cartridge and to a method of opening such a shutter.
2. Description of the Related Art
In related-art image-formation devices such as copier machines or printers, a photosensitive drum and a development roller are contained in a single case, so that the photosensitive drum and the development roller are replaced together by simply replacing the case. Process cartridges based on this configuration are widely available in the market. One requirement for such process cartridges is accurate positioning of the photosensitive drum and the development roller with regard to an interval therebetween. The positioning of these components is generally conducted by providing holding members for securely holding rotation shafts of the photosensitive drum and the development roller and by fixedly mounting the holding members to mounting parts formed on side plates or the like of the case.
The holding members, unfortunately, are bound to have undesirable variations in the size precision thereof, and, also, the mounting parts have variations in positional accuracy when they are formed on the side plates of the case. As different types of such variations are accumulated, the positioning accuracy of the photosensitive drum and the development roller suffers degradation.
Accordingly, there is a need for a process cartridge which can provide accurate positioning of a photosensitive drum and a development roller, and for a method of creating such a process cartridge.